15 Orionis

15 Orionis is a suspected astrometric binary^[9] star system in the equatorial constellation of Orion, near the border with Taurus. It is visible to the naked eye as a faint, yellow-white hued star with an apparent visual magnitude of 4.82.^[2] The system is approximately 340 light years away from the Sun based on parallax. It is moving further from the Earth with a heliocentric radial velocity of +29 km/s,^[4] having come to within 69 light-years some three million years ago.^[5]

15 Orionis

Location of 15 Orionis (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Orion
Right ascension	05h 09m 41.96481s[1]
Declination	15° 35′ 49.9051″[1]
Apparent magnitude (V)	4.82[2]
Characteristics
Spectral type	F2IV[3]
U−B color index	+0.19[2]
B−V color index	+0.32[2]
Astrometry
Radial velocity (Rv)	+28.79[4] km/s
Proper motion (μ)	RA: −3.105[1] mas/yr Dec.: –3.444[1] mas/yr
Parallax (π)	9.5097±0.2951 mas[1]
Distance	340 ± 10 ly (105 ± 3 pc)
Absolute magnitude (MV)	−0.04[5]
Details
15 Ori A
Mass	3.42±0.67[6] M☉
Radius	5.9[7] R☉
Luminosity	300[6] L☉
Surface gravity (log g)	3.75[8] cgs
Temperature	7,161+50 −49[6] K
Metallicity [Fe/H]	+0.21[8] dex
Rotational velocity (v sin i)	60[6] km/s
Other designations
15 Ori, BD+15°752, GC 6306, HD 33276, HIP 24010, HR 1676, SAO 94359, CCDM J05097+1536AB, WDS J05097+1536AB
Database references
SIMBAD	data

The primary component is an early F-type subgiant star with a stellar classification of F2 IV,^[3] a star that has exhausted the hydrogen at its core and has begun to evolve into a giant. It has 3.42^[6] times the mass of the Sun and 5.9^[7] times the Sun's radius. The star still has a relatively high rotation rate, showing a projected rotational velocity of 60 km/s.^[6] It is radiating 300 times the luminosity of the Sun from its expanding photosphere at an effective temperature of 7,161 K.^[6]

It has one suspected companion, component B, at a separation of 0.3".^[10]